Most any unused port is valid for receiving mail from your e-mail clients, port 587 is normally used for mail user agents.  Mail sent from other servers to MercuryS though must be received on port 25.  You can configure MercuryS to use port 587 as well as port 25 and you can also use TLS secure links and authorization.  Mail servers sending through MercuryS may or may not be able to use the secure connection so you must not disable the unsecured connections.

I've recently been advised that some servers are now transmitting on port 587 versus 25 per RFC 2476.  My question is that from the researched I've done I can't find when this change has been approved if it has.  Can somebody tell me if we are now to configure Mercury to use port 587 for SMTP-Auth?  And if so what needs to be done?  Any comments on this subject would be appreciated.

Thanks